In order to support the Superfund Program, we propose to establish a Biomarker laboratory Core that will combine the resources and facilities at the School of Public Health, UC Berkeley, the Laboratory of Molecular Epidemiology, UCSF, and Children's Hospital Oakland Research Institute. The main goal of the new Biomarker Core is to facilitate the collection, processing, and analysis of samples for epidemiological Projects 1-5 using established molecular and cytogenetic methods of analysis and to assure appropriate handling, storing, banking, and testing of these specimens. This core will be involved in the acquisition of handling, storing, banking, and testing of these specimens. This core will be involved in the acquisition of specimens from childhood leukemia cases and healthy controls of different ethnic backgrounds (with Projects #1-2); arsenic exposed children and adults from India and/or Chile (with Project #3); and benzene exposed workers from China (with Projects #4- 5). Laboratory protocols for sophisticated sample processing, including cryopreservation and storage in liquid nitrogen, will be established for cord blood, peripheral blood, buccal and urothelial cells, and sperm specimens. Routine characterization of these biological samples will include DNA/RNA isolation and storage; mutational analysis of the N- RAS gene; genotyping of a panel of cancer susceptibility genes; characterization of the cytogenetic traits in childhood leukemia cases by reverse-transcriptase PCR and fluorescence in situ hybridization; and analysis of cytogenetic damage in different cell types by the micronucleus assay. A computer database will be created to manage sample tracking, recovery, and transmission throughout the core and the Superfund program. These services will greatly enhance the ability of the epidemiological Projects #1-5 to achieve their goals. Establishing a biomarker core for laboratory analysis is an efficient use of resources of the Superfund program as UCB, UCSF and CHORI collaborators are already capable of performing all of the assays required and can do so without incurring the expenses of an outside laboratory. A unique bank of tissues and DNA/RNA samples will be established from children and adults of different ethnic background for use in future of cancer risk from genetic and environmental factors.